The Prime Minister used his speech to the Tory party’s conference to suggest that anyone under 25 would not be able to claim housing or unemployment benefits under an all-Conservative government.

He said that “bold action” is needed to ensure that young people do not “opt for a life on benefits”.

However, in a sign of a further Coalition split over Tory welfare plans, Mr Clegg said that he is not in “favour of blanket removal” of benefits based on age.

It is thought the Tories will put their proposals in their next manifesto. The tough measures on welfare could put a strain on any future coalition negotiations with the Liberal Democrats in the event of a hung Parliament.

Currently, those who refuse to take a job or an offer of a training place can lose their job seeker’s allowance (JSA).

However, under Mr Cameron’s plans the Tories could cut or remove housing benefit payments if under-25s do not find work or go start a training programme.

Speaking to LBC 97.3 Radio, Mr Clegg said that he is in favour of plans for greater “conditionality” on benefits for youngsters.

“So actually this idea of what they call in the jargon ‘conditionality’, so you can’t just say ‘I’m going to cross my arms, sit on my sofa and not try’, let’s look at that. I’m not yet entirely clear what they have in mind, the Conservatives, but we’ve worked on this before, we’ve done quite a lot of it in government – you can’t get JSA, you can’t just receive JSA unconditionally at the moment.

"If you don’t take up the opportunities given to you, after a certain point it can be taken away from you anyway. We changed those rules just recently.”

However, he said: “I’m not in favour of just blanket removal of people just because they happen to be a certain age.”